Telephone-exchange system.



E. CLEMENT'.

TELEPHONE EXCHANGEI SYSTEM.

APPLICATION FILED NOV. 2l, 1905.

Patented Aug. 11, 1914.

7 SHEETS-SHEET 1.

. I lllli witnesses IIII-IIIIIHHI E. E. CLEMENT.

TELEPHONE EXCHANGE SYSTEM.

APPLIQATIOH FILED NQV. 2l, 1905.

Patented Aug. 11, 1914.

'l SHEETS-SHEET 2i.

E4. E; CLEMENT. TELEPHONE BXGH'ANGE SYSTEMu APPLIOATIQN HLBD'NQV. 21, 1905.

Patented Aug.A 11, 1914.

AS20 lS12/S70 n E. E. CLEMENT.

TELEPHONE EXCHANGE SYSTEM.

i APPLICATION FILED NOV. 21, 1905. 1,107, 140. Patented Aug. 11, 1914 E. RULEMENT.

TELEPHONE EXCHANGE SYSTEM. l PPL'IGATIQN FILED Nom-21, 1905, 1,107,140. Patented Aug. 11, 1914 7 SHEETS-SHEBT 5.

E. E. CLEMENT.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED NOV. 21, 1995.

E. E. CLEMENT.

TELEPHONE EXCHANGE SYSTEM APPLICATION FILED NOV. 2l, 1905 1,107,141), Patented Aug. 11, 1914.

7 SHEETS-SHEET 7.

witness@ iuNiTEDe sTATEs PATENT oEEioE.

,Estiman E. CLEMENT, 0E WASHINGTON, DIsTEiCT 0E COLUMBIA, fis-SIGNOR, Br MEsNEAssIGNi/IENTS, To FREDERICK c. sTEvENs, or ATTICA, NEW YORK,-

V TELErHoNE-EXCHANGE SYSTEM.'

incarica l 9 "teins, oi `'which the following is a specifica' tion, reference being had therein to the accempanying drawing.

ltiy invention 4relates to Ltelephone eX- change systems, and has torvits object the improvement ot `such systems in the particulars wliichwill be hereafter enumerated.

My invention is designed.toper1iiit a calling subscriber, by the proper and very simple manipulation oi1 a 'piece of apparatus called a sender at his substation, to connect his line with the line of any other subscriber in the exchange, whether the exchange is,

large or small.

llierinvention is directed first to the prosubstatien, which may be' used at night. as well as in the day; second, to the reduction of apparatus required at the central oflice,

by providing a number of automatic switch ingl devices less than the' number oi' lines, a callingl line being connected manually by an operator to the switching,` apparatus which it will thereafter control; third, the invention ils directed to a selective device com posed entirely ot relays, no particular type of relay being required and no moving me;` chanical Kparte other than the ordinary relay armatures beinp` employed. ln the system l shallvthscribe these relays are used iioi' se lective party-line work, but they are available fcr any purpose of selection, and may be usedl'to replace the automatic selective switches which are also described for the purpose ci connecting` lines.

The speciiic system herein presented is what is commonly called semi-automatic.

Subsidiary points and features of invention will appear from the following detailed description as I proceed.

lt will be understood that while all of the portions of the present system which are presented herein mutually contribute to the unitaryA result of eii'ecting connection between subscribers in the exchange7 seine of the, pieces of apparatus may be used in any system, such as the subscribers sender, and the selective party-lineapparatus.

Specification of LettersPatciit.

Application filed November 21, 1-905.

Patented Aug. 11, 1914.`

Serial No. 288,368.

an improvement in semi-automatic systems i it 'will be apparent ythat the'improvenients may be equally applicable to full automatic Y systeniswith slight modifications in the central olice connective links. Y

My improved subscribers sender is a selfcontained unit, which in its simplest form Y merely makes and breaks the metallic circuit, consequently can be attached to any common battery telephone Without change in v the wiring. In order to make it useful at night I add, as I shall hereinafter show, a sin-all incandescent lamp which is contained .Within the device, and servesto illuminate the numbers While sending. `[The Working ,4 parts oi this sender are contained within a cylindrical shell and an end cap constitutingu the handle or wheel by which the numbers areA sent. rlhe shell is intended to be attached to the transmitter shell ofthe telep l phone with which' it is to be used, theilnuinvision' of a simple and reliable sender at the bers appearing behind a small. window-as the wheel is turned. Vhen the lamp is used to illuminate these numbers, a ground wire is required.

To reduce the apparatus at the central elice, l` provide each line with the 'ifdiiiary land welhknown answering-jack 'and-line rsignal. When a calling subscribery .removes receiver froiniits hook preparatory to sending a number, his operatoratv the central oflice inserts an answeringplug into ".lliis jack.` This plug forms the terminal cf j a cord-circuit which passes to a first seleeteu switch. When the operator has connectedv the subscriber to the switch, battery is supplied to the line 'as to light up the4 lamp in his. sender,

in such manner thereby notifying him so that he may prof ceed to send the number he wants. rIfhe opl' .eration of the rst and subsequent selector and connector switches in response to the subscribers sender, is substantially the same as in full. automatic systems. The switches oit themselves constitute no essential part of the present invention, except as elements in the combinations I shall set forth. Certain features of the cord-circuit, and certain relays employed therein, are in themselves' novel, and consttute'fm'atters of invention, but these will be subsequently pointed 'ont and claimed.

The selective relay scheine Which-will be v 'described herein as' applied to party-line sel/Vhile. Il have spoken et the invention as lecting, and which I. have said muy ybe used;A

li o

range relays, I shall claim the same broadly.-

with a` plurality of transmitting wires. Il

' taneous and whose results are much more for other purposes, involves the use of a double sctof interlocking relays controlled through the front and back contacts of a. moving;l arm, which is conveniently an armature of a relay. Suppose the relays in one set are called for the moment 1, 35, 7, etc., and those of the other set are called 2, 4, 6, Then the operation is that when the control reiztT pulls up, current is put on a lockingl circuit common to all the selective relays. Then upon fallingbach the control relay closes through No. l, which pulls up, locks itself, and connects No. 2 to the front contact of the control relay. It the single motion of the control relay is all that is made, that is, if but a single make or break has been received, then nothing further happens.` It, however, a second impulse Iis received, the control ,relay aga-in pulls up, thereby closing the. circuit of No. 2, which pulls up and locks itself, at the saine time connecting No. 3 to the back contact of the control relay. llVhen the latter again lets go, No. 3 pulls up, locks itself, and connects No. 4r. to the front Contact of the control relay. A t this stage, there have been two impulses received, two complete movements of the control armature, and one change in the selective relays, together 'with a preparation for a second change. To speak more specifically, suppose there are four generators of selected ringing current, one of whichv is normally connected to the ringing key or relay. Any one ot these may be vselected and put on the ringing,` keyby sending l, 2, 3, 4t impulses. rIhe first impulse sets the guard relay No. l, which prepares No. 2 or the activo relay, 'but does nothing` further, hence a single impulse will leave the No. l generator still connected to line. A second impulse will work No. 2 relay, cut ott No. 1 generator, connect No. 2 generator, and prepare relays 3 and 4; for the next step, and so on. I consider .this arrangement of selective relays a very important feature of my invention, and as I believe'I am the irst so to ar- I am aware that various combinations of relays have been used heretofore for purposes of selection, but always, so far as I know have here produced an arrangement which can be controlled from a distance over asingle wire, whose action is practically instancertain and dependable than those of any form of switch mechanically moved. In order to select any one of ten numbers or connections, or what not, a maximum numberof twenty-one relays is required. In order to select any one of the same number with a mechanically actuated switch, two

relaysfand two magnets, aswell as all. the? moving mechanical parts and contacts are required.

A very marked point of su pcriority in my arrangement of relays over anything of the hind heretofore produced, is its adzqitability to perfect protection from dust and moisture. My relays are }.ircferably mounted on the regulation racks, iii standard dust-proof shells, or covers, and the expense ol maintenance or' a system employing them .should be so low as to be almost negligible, since there are no parts to wear, all contacts can be made of platinum, and all joints can be soldered solidly.

llVhile I shall not present specific claims herein, for my relay selective scheme as a. selector or connector switch, I shall claim the scheme broadly, as I have already indicated.

My invention is illustrated in the accompanying drawings, in wliich Figures l and 2 are respectively a front and a side view oi my improved subscribci"s sender. Fig. 3 is a longitudinal sectional view thereof, and F ifr. is an end View similar to Fie. 2, but with parts broken away to show the retarding or governing mechanism. Fig. 5 is a detail view of -the number drum or cylinder removed from the case. Fig. G is a side View of thel sender att-ached to a transmitter, and taken from the opposite side to Fig. 2. Fig. 7 is a diagram or' a subscribers line-circuit, an operatrs cord-circuit and a lirst selector switch. Fig. 8 is a diagram complementary to that of Fig. 7, showing the contact banks of the first selector switch, a second selector, and a connector switch, the latter containing onlyr individual-subsci'iber lines. Figs. 9 and 10 are respectively a iront and a sectional View of my relay selector set, in a form designed for use with automatic connector switches for four-party selective ringing. Fig. 11 isla diagram similar to Fig. 8, and also complementary tothat of Fig. 7, showing a connector switch equipped with the four-party selective relay set of F ig. 9. Figs. l2 and 12=1 show a type of automatic switch which may be employed in the system, these figures being added in order to complete the. illustration. Fig. l2a is a detail of the switch banks.

In describing' this system, with reference to the drawings, a great many reference characters will be required, and I shall theretore adopt the following` system throughout: l shall designate each piece of apparatus by a letter, and shall. number each part of such piece. It is to be understood that the letter' and each ot' its subsidiary numbers are to be read together. Thus I shall call the subscribers sender, shown in Figs. ,1. to 6, S, and in these six figures, instead of writingr i, S2, S3, S4, etc., I shall write simply l` 2, f3, 4, etc., throughout the spcciic description of the part S. In the diagram, however. where the various parts appear together', and conusioninight be caused by having the'saine numerals re cated, these numerals If the lamp kis to be used in the sender, a

groundwireis also led through this arm, and connection with all the wires is electcd in' the'shell 2. The sender. itself, S, is best shown in Fig.' 3, all' the working parts here being in section, and removed from the shell 1 which is permanentlysecured to the transmit-ter shell 2, as clearly shown in Figs. 1, 2 and 6. The sender shell 1 has a window2, through which the numbers upon the indieating cylinder are .visible as the handle 3 is turned.y This handle 3 is a milled flange formed on the disk 4, whose hub 5 is rigidly secured to a tube 6, whichfs'erves to connect the, handle and the operating disk 7, which is also mountedrigi'dly on the tube by means of nuts 8, but insulated therefrom by bushings 9. fThe handle and disk are normally maintained in a fixed zero position by the spring 10, housed in av chamber formed in oneend of 'the frame 11, between an outer diskor cap 12 andan inner disk or bearing partition 13. The spring is secured at yits innerend to the tube G and at its outer end to a'stud 14, fixed inthe cap 12. The normal or zer-o position, of the disk is accurately determined by the stop 16 fixed to Y the iframe l1, and a pin, 15, on the disk, 7.

The frame l1 `comprises two rings, 18 and 19, one at each end, joined bystraight parallel members. The one end, as I have said forms housing for tneeaetuating spring 10, and the' other end supports the contact springs and the lamp. F or this purpose the vsprings 20, 2l, 22, 23 and 24 are piled up between insulating slips 17, and secured tof-the ring 19 by means of the screws 25. Springs- 2O and 21 are Vthe line-signal springs, nor= iiially closed; spring 22 is the lamp' spring,

normally open; and springs 23 and 24 conistitute together a socket or 'ack for the reception of the lainp 2G, which has 'the usual coperating contacts, 27.

The disk 7` carries a number of steel pins,v 70, arranged in a circle, and they ure vall rather small in diameter or flattened and each inclined edgewisc to a spring 20, for-a vpurpose which. will,.presentjly appear. As

the handle is turned these pins pass over the end of the spring 20, which is likewise 1nclined, so as to vform camsurfaces with its two faces. .Vhen the spring ll() turns the tube 6 the handle and the disk back, the pinsJ rapidly over the contacts.

.70 pass successively under the end of, the' spring 20. I'

' theeentral oiiice, the subscriber pressesin the button 28, which is normally kept V'out from .the hubhy' 'the coiled' spring 29and which is secured to the spindle 30,

' whieh passes through .the tube. 6 and the tube 6 turnsy the latch block 31, soI that its point or edge disengages the spring 22, breaking the Ilamp circuit and permitting the spring 29 to draw theblock back. In order that the block 31 will turn with the tube 6, -I provi de the spindle 30 with a pin 33, Working in a slot 32 milled in the end of the tube 6.

.The retarding mechanism which prevents the tube 6 from being turned back too rapidly by the spring 1G, is housed within the hand-wheel, in order to save space. This consists of. a pair of friction members 34 pivoted to afreely rotating disk 35 journaled on the tube 6. This disk is rigidly se'- cured to a pinion 36 meshing with an idler wheel 37 which takes into 'the internal gear 38 cut on the inside of the milled lflange 3 of the hand-wheel 4. ll/Vhen the wheel is turned -forwardly or in theldirection ofthe arrow, Fig. 4, to -set a number, the idlerwheel turns with it, and turns the pinion 36 and the disk 35 oppositely, so that the friction members 34 are drawn loosely around'.- the smooth inside surface'38 of the flange 3. When the wheel is released, however, `and starts to return, it rotates the idlerwheel and the pinion 36 in the reverse direction,

whereby the friction members 34 are thrown out aeainst'the inner surface 38 andb C 7 1 reason of their shape and the eccentric manner of their pivoting, they develop consider able friction against the inside of the'flange 3, thus retarding the return of the wheel so as to prevent the pins 70 from passing too As it would ordinarily be dilicult to turn the wheel 3 completely around to the higher numbers, such as 9, lwith a single. motion of the wrist, I previdea locking cam39, carr ried in a bracket '40 secured to the plate 4l.

This cam bears on the milled edge of the wheel and prevents its retraction, so thatthe wheel vmay 'be turned by several motions'or steps to a desired number, and may be re leased by throwing the cam 3 9V out of engagement with it. r I

Before proceeding to any description of the circuits in the presentcase,

describe the typical sitch andthe selective.

I will briefly l a spindle 3, a vertical magnet 4, a rotary magnet 5,-a private or test magnet G, and a release magnet 7. The spindle carries wipers to cooperate with the contacts inthe banks 2, and is fitted with a rotary ratchet 9 and a vertical ratchet 8, the former engaged by a pawl actuated by the magnet' 5, and the latter by a pawl under the control of the magnet el. A detent pawl 11 has two arms which engage bot-h the rotary and vertical ratchets, being lifted therefrom when it is desired to release the switch, by means of a link 12 on the armature lever 1.4 of the release magnet 7. The latter being energized, pushes forward the link 12 until it engages a pin 15 on the upper or bell-crank armof the double dctent 11, and when the magnet is denergized the retracting spring 16 throws over the pawl to disengage it' from the ratchets. r1`he circuitssof the controlling magnets of this switch are completed and broken in proper sequence by what I shall call ay side-switch 13. This comprises a set of arms mounted together and sweeping over contacts 19 forming the terminals of the different magnet circuits, as will presently appear in the description of the diagrammatic figures. -The pivoted lever carrying these springs has a finger on its upper end engag ing the escapement 17 'controlled by magnet G. A spring 20 tends to throw the .lever I over, but is only permitted to do so one full step for each complete double motion of at- 'traction andrepulsion of the armature of magnet 6. l/Vhen the switch is finally restored by the release magnet 7, .and the spindle 3 drops into the position shown in Fig. 12, the lower edge of the rotary ratchet wheel 9 engages the shortarm of a bellcrankA 18, the long arm of lwhich pushes back the side switch lever to its normal position shown. The frame 1 in the figure. is supposed to have a back 21,` upon which the various parts may be mounted.

Fig. 1,2u is a bottom plan view showing the switch banks 2, and the wiper arm 10.

vThe contacts are arranged in curved rows forming a portion o f a cylindricalsurface, whose axis is in the middle. The upper end of the spindle is provided with a cap 22, in which is a coiled spring having one end secured to the spindle, and the `other to a rod 23, journaled on the spindle at one end, and on a post 2li at the other. Attached to the spindle is a stop-arm 25, and these parts operate as follows: Sliding on 'the post 24, the parts 23 and 25 permit vertical movement of the switch, and the spring in the ,cap 22 turns the spindle around'from positionin which it may be, to the Zero position with the stop-arm against the 4lip on the arm 23, when the detent 11 i's lifted.

The selective ringing device, shown in Figs. 9 and 10, will be designated by the letter K. It has a base pla-te 1, with an upstanding flange 2, on /which are secured relays 3, 4., 5, 6, lfand 8. Upon the opposite side of the ange from these relays is a master relay 9, which is made sluggish, for a purpose which will presently appear. This relay consist-s of a solenoid 10, with a ver tically sliding core 11, carrying a head 12, of insulating material, and having its lower end supported onan adjustable stop 13, when the solenoid is denergized. The solenoid winding is formed on a hollow spool, preferably having its tube of brass, and its heads of rubber or hard liber. Around this is the magnet frame 14mm-16, of soft iron, the core 11 being also of soft iron, but bushed with copper or brass at the point where it passes through the frame, in order to prevent sticking. Upon the member 15 are mounted contact springs 23 to 30, in-

elusive, with their lower ends adjusted to be moved by the head 12 when in its lowest position. The springs 23, 26 and 29 are secured together by insulating connections, so that they all move as one. On the meinber-lG of the iron frame are secured the contact springs 17 to 22, inclusive, on which 18,-19 and 21 are secured and -moved together. springs mounted on the solenoid frame and operated directly by the core foi-the sake of simplicity in tracing the circuits, which are sufficiently complicated in a system of this kind, without adding eXtra features. In practice, however, I wish it understood that the solenoid relay 9 has not as many contacts as are Shown in this ligure, being iitted, preferably, with only one pair of up contacts and one pair of down contacts, all the rest being mounted on relays of the same type as the relays 3 'to 8, and carried on the same support. The purpose of employing this solenoid is to produce certain circuit chauves of appreciable duration, in order that tlie selective relays, 3' to 8, may be operated to select without connecting, during the said circuit changes. To put this more specifically, the solenoid is the master relay, which, on being energized, cuts oil' the generator circuit entirely, and maintains it cut olf as long as the core 11 is drawn up. The top of 'the tube of the solenoid is provided with a valve 31, which rests upon the cap 32, by gravity, with its stem sticking down into an opening through the cap. By regulating the weight of this check valve, and the closeness of the joint it makes with the top of the cap, I can regulate the relative speeds of the up and down movement of the core 11, to a nicety. The

core is moved up 4very quickly, the check.

I have shown all these contact" movement of the core is much slower, so

. which operate the relays 3, 4, 5, 6, 7 and 8 for it to pass oli. of the extended end oil,

the spring 21, the operative or changed position of the upper set of springs being'thus maintained until a break in the circuit occurs, of suiiicient duration to permit .the

slowly dropping core to pass od' the spring 21, when the upper set of springs connects the ringing 'circuit to line, together with the. particular generator of current that has been selected, and this connection is maintained until the head 12 reaches its lowest position, as determined by the stop 13, when the lower set of springs will be operated to again cut oli' the generator. The further operation of this device will more fully appear from the description of the circuits, to

which I will now pass.

F 7 and 8 aretov be read togetherin the iirst part oi the description, which will be limited to the case where the lines to be called are single-party-lines.

Figs. 7 and 11 are to be read together in the second part of the description, referring' to party lines and selective signaling.

Referring now to Figs. 7 and 8, and particularly to Fig. 7, A is a subscribers station, having line-wires l and 2 extending to the central oiiice, where theyterminate in contacts of a cut-off relay N, normally connecting them to a line-relay M, on one side, thence to the main battery B, and to ground on the other side. At the subscribers station I provide the usual transmitter, re-v ceiver, ringer', condenser, and switch-hooks, which need no special description. In addition to these I provide the sender s, which is shown in Figs. l to 6. Their operation will appear later. The springs S20 and S2L are normally closed together, and are included in thetalking circuit. The spring S22 and the lamp S26, normally disconnected, are in a ground tap.

At the central oflice the line has a terminal jack J, with which the answering plug I cooperates. This plug forms the terminal of a cord-circuit, 5 6, connected through condensers, C, with the trunk circuit 7-S of an automatic selector switch F. This selector switch is of the type shown in Figs. 12 and 12a, and the, descriptional- *y ready given thereof makes it unnecessary todo more than prim'J out the one di florence between a selector and a connector switch. The description already given of the switch is for a connector, that is to say, a switch containing the terminals of one hundred subscribers lines, and adapted to have its' i, spindle stepped'up to the desired contact in the row by a definite number of impulses. In a selector switch, on thev other hand, the spindle is steppedup to the desired row of contacts, (the contact banks being the saine as the connector) and then is stepped around the row bya continued and automatic action of the rotary magnet, uiitil an idle l therefore, the'side switch uninoved, during 'oi'i magnet 5, dr, in other words, until an 1 idle trunk has been reached.

that further .description is unnecessary. The relays are follows: F3 is Vcalled the i vertical relay, and F31 the rotary relay, these being arbitrary designations, the former controlling successively the ve private magnet F3. They jointly control the circuit ofthe release relay F32," .vliich con-A i tro-ls' the release magnet lll. I"llie relay F30 :The other circuit connections will sul- 'ficiently appear v from the description of the operation hereinafterv The cord-circuit 6 has a pair of bidge relays It and T,

lThe relay I is connected iii parallel with tlie lamp R2 -from the back Contact of the iwhile relay Il is connected from the` front ground. Each of these relays, in its mechanical construction and mode of operaytion, is the same as that illustrated in Fig. 9, the only diiference being in the number ,The relay I closes ltogether its springs I 'and I2 when it pulls up in passing, making fa momentary closure, while relay L closes the three springs L2, L3 and L4, and opens ing this condition continuously. The operation of this will also suiliciently appear hereinafter.

Referring now to Fig. 8,-I show there- .secondrselector, which I designate at F0, and a connector. switch designated as 'the circuit connections of these/switches trunk is reached, when the switch Stops. 7o

the armature 29 of the magnet 75 i tain the armature of magnetattracted, and,

thecontinued yibrat-ion of the armature 29, l

In Fig. 7 the various parts are marked so 85 l and .rotary magnets, and the latter cont olling the is connectedby wire 9 to the first and sec- 95 ,.theyare both grounded through wire 15.

iand also a pair of solenoid relays I and Ii.

armature R, by wires 86 and 33 to ground;

i contact of the relay R by wires 37 and to 110 land arrangement of the contact springs,

the pair L-L2, when it is down, maintainvin another selector switchj known as the QFX. The individual mechanical parts and' are the same as already described 'for 130 the switch E, with the exception of the ringing portion of the connector circuits which will now describe. When the side switch arms F33 and F34, of the connector switch, pass onto their third contacts they connect the Wires and 101 to the'terinh nal Wires 11G and 120, corresponding to l1 and 12 of the first and second selector@ rEhe ringing relay G then becomes connectedl through the wiper arm F13 to the Wire 180,

which runs back to a pair o1c contacts 181 or' the private vmagnet F. Nhen the last rotary impulse comes in through the relay F31 of this switch, the magnet, FG, opens this ringing circuit and closes the test, and when the next Vertical impulse comes in through rela ground at 2%, and relay G becomes energizecl, connecting the ringing generator G to the Wipers F10. The trunk circuit through the connector is broken hy the condensers C, and in order to supply battery current to the called Subscriber i provide the bridging magnets F40 and F 11, through Ywhich the main battery is connected to the conductors 10G and 101.

The foregoing` is suilicient to enable the operation of an individual line to be understood.

l" will. now take up Figs. 7 and 11 together, and 'explain the operation of partylinos with Selective ringing. in Fig. Y, the first selector is shown, and need not he described again. in Fig. 11 the circuits oi" a connector switch only are given. The tiret: selector and connector, taken together,- are sufficient for an exchange having` more than one thoueand subscribers, but it' the .exchange is to be larger, say about ten thousand, then a second selector, like FO, in Fig. S, must he interpolated` between the first selector, (Fig. 7) and the connector, (l`ig. 11). The only description :necessary for understanding the party line work is that of the connector', since there no change whatever in the second selector, if that be employed. The connector apparatus and circuits are also the same as in Fig". 8, eX- cept as to the connections and operation of the ringing relay. In Fig. S thisis a plain relay, G, with springF contarte 'normally closed connecting` the wireb` 100 and 101 to the switch arms and lli. I

ligxill differs from l? S in its showing of the circuits or' the connector switch in one respect only, that is, instead of the ringing' battery l, and' on the other side to the wir F36 the circuit ).Stliis closed to 115, leading` to the third contact of the side switch arm FW. Thus, in the third position ot' that ainnwhen the Irelay F3" is energized, current will llow from the ground Contact 270 back thro-ugh the contacts 181 and the wire 180 to wire 115, and the relay@` KX K,

in parallel, and so to battery. and lroin batterythrough the ground lo 2T() again. The

relay KX quick, and the manier relay lil is rery Slow, being, in tact, a .erden-oid with a plunger core, as already described, in connection with Figs. tl and 1t). The 'Function ol" the master relay, ,stated reiv briefly, is to disconnect the generator and connect the wire-S` 1GO and 110 ou the one ldde, and 101 and 1Q() on the other, when it' is down; to disconnect these wires when it un or at; any intermediate point, to dieronnecl, the generator also when it ie in it. uppermost position, at the saine time cloning the hattery throueh contacts lil and l onto the armature KU of the relay KX, through the wire 11G, which l shall hereai'ter call the workinnr wire, Since it furnishes current. during selection, for the variou -t relays, l", ii, etc. in this, figure therey arel lli/)wn V['our generadores-G2 titi, tlf and (ffeall connected on one Side to r conunon return wire l1?, and on the otl .side hy individual wires 11S, 121 and i315, to trout: contacts on the relayer K3, l?. K, the generator (la, however, being connected by wire 11S) tio a hack contact en the rel f l, this?` particu lar generator heinnjilierc normally connected in circuit, with the wire.I lli' and 123. These two'wires` mss to the springe lim and lil, respectively, ol' the nnmter un lay K, through whose action, as already explained, they are (annum/.ul zo und dira-onnected from the wires and lill, in a manner that will more fully appear from the description of the operation. whieh will now be taken up. v

The operation oli' an individual line circuit, is substantially the saine as that oi'f a 'l'ourlparty circuit, except in the tinal .eelcctioin l will therefore comun-nce with Figs. and 8, and then read the operation upon both Figs. 8 and.

idle will assume that Subscriber A is calling: He presses in the button S2s,where upon the latch Si engages the Spring 22, and is detained thereby. He then removes his receiver from the hooi: Il, closing the circuit of the line relay M, by way of B,M, 1,

S20. S21 transmitter and receiver H. 2 and ground, which lights the lamp 7n, by means of current flowing from the battery B through the local lampv circuit VAto ground. Although the lamp S2 at the sub-station is connected through the frame of the device and syringe S20, SEL, to ground from the linr wireait gets no current, for the reason that there is a dead ground between .it and the llt) (ill

.tip side, B, '.lf. 3E,

not normally visible,

Vappears opposite the window S2,

at the back Contact of the cut-oh? relay lil, When the plug l? is inserted battery is reversed, the ground battery then going on the sleeve side 6, and the ground on the 6, P, si, d, N and ground, also through 2, SM, S26, S23, S22, @Bland through the trame to ground, whereupon lamp S2 at the sub-station gets current and lights, illuminating the opaque cylinder carried by the disk S7, in `Fig. 3, and-showing up the Word Llila/mbar, which, when the parts of the sender are in their normal position, rests opposite the window, but is because it is printed on theinside of the paper cylinder. In the drawings this cylinder is shown threaded, but in practice l have found it best to make it of paper or similar material. The Word y llumber thus exhibited, is the same as if the operator hassaid f Number to the subscriber, and he then proceeds to send in his number vby manipulating the hand-Wheel S3, in the manner described, in connection with Figs to 6; 4

hach time the Wheel is turned around until a certain number on the paper cylinder I the lamp blinks and dashes, so that even iii' the ,numhers are not watched carefully, the recurring flashes can be counted. As long as the subscribers receiver is ofi the hook, and the plug P in the jack J, the relays T and R are energized. Breaks in the metallic circuit, due tothe pins S70 lift-ing the springs, work the armature R back and forth, Hashing the lamp R2, pulling up the solenoid I, over the path B, through contacts ofv T, wire 35, R', 36, I, 33 to ground, as well as the solenoid L, over the path B, contacts of "ll, R, 37, L, 33 to ground, keeping both et them energized effectively, long as the armature R is oscillating, and sending impulses over the path lli, contacts of T, 35, R', i6-31, L', L2, 28 to the vertical side 7 of the trunk circuit of the First selector switch -F and through its vert-ical relay by way of lim, 9, F3, l5 'to ground. This. works the relay F50, which works the rerticamagnet F4, over the circuit l, F4, i6, 25, 27 lto ground, which steps up the switch spindle F3 as many steps thereare breaks. The final make of the first set pulls up the armature l', lets go the solenoid' l, and a single impulse is sent over the path l, contacts of Rf, SAL-32, P-i, 29, to wire 85193510,

the rotary relay F31 and 15 to ground. This relay Worhsthe private magnet F8, over the circuit B,`l9, F, 26, 27 to ground, which advances the side switch arms one step and starts the rotary magnet F5, over the circuit ll, F5, 17, F13, 18 to ground, Whichsteps around the spindle F3 continuously, until the wiper F10 of the wire 13 nds a contact is! not groundedor busy. Thereupon lis on the second point. 1

the private magnet F5 lets go, and the side switch goes around another step, the first selector stops, and wires Zand 1l, 8 and 12, are completed, and the circ`V to the second selector, sl n in Fig. 8, and ground is put on the test wiper F10 through 13, F32, 22, F 35 through its last contact to ground, thusoccupyicg andputting a busy test on the bank term ials selected as far as other selector switches may be concerned. The operation here 'for the second group of breaks the same as that already described, the first selection having been for the second selection for the hundred leaving the tens and units to foilow. 'n either Fig. 8 or ll this Imuch of the selection isthe same. The third group of breaks brings impulses through wires 7, in-Fig. 7, and the vertical wires of the 'second selectors andthe connectors tothe vertical relay F3", Whichworks ot is put through? produced by the sender S is precisely the thousands, and .l

the vertical magnet and steps up thev spindle of the connector switch'FX to the' desired row of tens. The next impulse from the rotary side 8 and the same side of the trunks to wire 80 andi relay F31 works the private magnet F6, steps ahead the side switch', outs l on the rotary magnet F5, opens tlielwire of the Vertical magnet until. FG releases, and the next group of impulses on the Vertical side 7-70 through the relay F3" turns thespindle until the desired unit in the row is reached. This much or' the operation 'is identical. for both Figs. 8 and 11, and the test is also the same, which consists in the next rotary iinpulse coming 1from the'side 8&8@ to -the relay F31, which causes the magnet FB tepull up once more, and closes the 'circuit of the test or release relay F32, since the side switch on the tip side of the line tested, the releAv Je relay F32 will pull up and release the switch. lf, however, the line is not busy, and hence there is no ground on its tip side, (thisbe ing due to the connection of a magnet F4, or a cord circuit magnet l, if the line is busy), the relay does not pui-l up, the mag net F lets go, the side switch 'goes the last step, and the wires lOOllO, and 1101-120,

are connected, While at the Sametime the switch arm F13 connects lthev wire' 180 with vthe ringing relay G, in Fig. 8,01' the two relays KL-KX', in Fig. ll.

H it is the switch shown in Fig. S the sublf thereis a ground.l

scriber now has control of the ringing relay G, and may, by sending a series of short breaks in indeterminate groups, cause the ringing relay G to pull up and put the gen erator G onto the called line. 0n the other hand, with the switch of Fig. il, the `called subscriber maygo farther, and-'sincehc has selected the line wanted, he may now, by means of the selective relays, pick out the particular` paz-'ty Wanted onthe line. In

order to dol so he sends a further group of one, two, three or four breaks. One break brings a single impulse to work the relay F of the connector switch, and this now werks through the Wire 115, causing 4'the master relay K9 to pull up to the limit, and then start slowly back, While the controlling relay KX pulls up and falls back-quickly. The

master relay breaks apart the springs K2 and K25 of one pair, and K29 and K28 of the other, putting the generator through springs K27 and K30 to the springs l 2--,K22, but taking it olf the wires 123 and 117, by lifting the springs K1 and K21 at the upper extremity of its movement. same time it closes battery onto the operat ing Wire 11G, and onto the locking wire 109. if battery were normally on the wire 116 the relays KA1 would get current, prematurely, and, of course, theA locking wire must be broken to clear out all the relays when the solenoid K is down. For one impulse the relay KX pulls up and falls back, doing nothing on the rip-stroke, but on the back-stroke energizes relay K4, which pulls up, locks itself through the wire 109, and connects the front contact wire 108 of relay KX to the relay K3. If the party Wanted is number' one, the subscriber does nothing further, and the solenoid. KD permits its core to sink gradually down, ringing current'being fed out to line from the generator G3, through the wires 117 and 123, and the springs K2", Y, and K30 K, through wires 110 and 120. rlCliis action continues as long as the head K12 of the solenoid is between the upper springs KIQ-K, and the lower springs KKL-K2'J ceasiu0` when it reaches the latter, 9 b

and the contact spring being then restored.

lf a seco-nd impulse comes from the calling subscriber quickly following the first, the relay K3 will pull up on the 11p-stroke of relay KX, locking itself on a wire 109, cut ott the generator G3, cutting on the gener-` ator G2, and connecting the back contact ot KX through the wire 107 to the relay KG. Whcn armature KO falls back, relay K will pull up, locking itself, in turn, on wire 10), and connecting 175 to the wire 10S. Thus the rst generator' has been cut-off, the sccond generator' cuton, and the next selection prepared by connecting the relay K5. lf no further impulse comes,.current from generator i2 will flow to line, as already de scribed; but if another impulse comes, the relay K5 will pull up, cutting ott' generator G2, and cuttingon generator G4, and so on, as the armature KO moves back and forth.

lt is apparent that while I have shown this set of selective relays applied thus to selective ringing, they may be similarly applied to almost any hind of a circuit or mechanism requiring selective action con'-A trolled over a single circuit or a single wire from a distance. shall therefore claim the At thel ricamo same broadly, considering myself to be the originator thereof.

Having thus described my invention what I claim and. desire to secure by Letters `llatent is: I

1. ln a telephone system, a substation containing a telephone having the usual substation ringer and an electric lamp, a line circuit extending from the substation, and a central station receiving the same, a connective link normally disconnected from the line circuit and a source of current supply at the central station, and means to bring the connective circuit into association with the tine circuit in response to a call thcrefrpm, and thereupon to supply current from the central station source to both the telephone and the electric lainp at the suliistation, whereby the subscriber is apprised of the tablishment of thecentral station connection.

9. In a telephone system, a subscribcfs station, a line circuit, a telephone including the usual substation ringer and additionally an electric illuminating device connected to the line circuit at the substation, central office connective means, norn'ially disconnected from the line but adapted to be brought into connection therewith in response to a call therefrom, and means at the central otlice to simultaneously supply working current for both the substation telephone and the illuminating device when said connection has been established, whereby the subscriber is apprised of the establishment of the connection.

B. In a telephone system, a pluralityof substations each containing a telephone equipment includ-ing the usual substation ringer and additionally an associated illuminating device, a plurality of line circuits extending froni the substations, a central ofiice receiving the same and containing a common source of currentJ supply and normally dis connected connective means for the lines, andmcans to associate the connective means with the line circuits when calling, and to simultaneously supply current from the ccnt-ral oliice source tlnfough a calling linc tov the telephone and illuminating device at the substation thereof.

t. In a telephone system, a plurality of substations each containing a telephone, a sending device and an electric illuminating 'device for the latter, line circuits extending trom-the substations, a central otlice receiving said line circuits7 a common source of current supply at the ccntral'oiicc, means at the central otiice for interconnecting thc lines, normally dissociated therefrom, and

means to associate'the connective means with any of the lines when calling, and thereby supply currentA over the line circuit to the telephone, the sending device, and the illuminating device, whereby the calling subscriber is enabled to work his lie 12. In a telephone exchange system a subscribers calling device and means for setting the saine, together with a return signal thereby connected to ground from the dry side of line, a central otlice battery grounded on one side and normally connected to line, means at thecentral otiice to eteet connection with the line in response to a call, and means for thereupon reversing the battery connection to line, whereby the return signal at the subscribers station will be energized, and whereby the callinO subscriber is apprised of the cent-ral oflice connection with his line.

13. In a telephone exchange system, a central otiice and substation, aline circuit conneeting them, means at the substation to close the line circuit to the central office, a source of current at said central oilice avail able for talking purposes, a signal energized thereby when the circuit is closed, connective means normally disconnected from the line, but adapted to be brought into connection therewith 'in response to a call, and an electric lamp at the substation with means to connect the same to the telephone circuit when the call is answered, so as to derive current through the line from the' central ollice source and indicate to the calling subscriber the connection of his line with the central station connective apparatus.

14. In a telephone exchange system, auto` matic switching devices, metallic line eircuits,` devices at the subscribers stations capable et making and breaking the metallic line circuits a definite number of times to control said switches, ringing devices at the central otiice associated with the automatic switching devices, and means whereby said ringing devices may be controlled by the same subscribers controlling devices and in the same manner as the switches.

l5. In a telephone exchange system, subs cribers lines and substations normally disconnected, connective links for said lines, ur telephone set, a signal receiving device and an illuminating device at cach substation and means for causing the operation of th',` illuminating device as a result ot the connection of a calling line with the first connective link, whereby the subscriber is apprised of the connection with a connective link.

16. In a telephone exchange system, subscribers lines and snbstations, normally disconnected connective links for said lines con taining signal receiving devices, a signal sending and a signal receiving device at cach station, an illuminating device associated therewith and means for causing the operation of the illuminating device as a result ot the connection of a calling line with the {i1-st connective link, whereby the subscriber may operate his signal sending device to -actuate the signal receiving devices of the connective links at the proper time.

17.- In' a telephone exchange system, subscribers lines and substations, connective links therefor, certain of said connective links being provided with automatic switches, impulse sending apparatus at said substations for operatingl the automatic switches, an electricI lamp ,associated with said impulse sending apparatus for illuminating the latter when operated, and means acting on the completion of the connection with the first connective link for causing the lighting of the lamp, whereby the subscriber may commence operation of his impulse sending apparatus at the proper time to effect connection through said automatic switches.

In testimony whereof I atiix my signature in presence of two witnesses.

EDIVARD E. CLEMENT.

Witnesses:

JAMES I-I. MARR, E. EDMONDSTON, J1'. 

